politsei

In a sentence

• Politsei patrullib tänavatel kogu öö.

  The police patrol the streets all night.

  Here, 'politsei' refers to the police force as an institution.

• Ma helistasin politseisse, et teatada vargusest.

  I called the police to report a theft.

  In this sentence, 'politseisse' is the illative case of 'politsei', meaning 'to the police'.

• Politseil oli kiire reageerida hädakõnele.

  The police had to respond quickly to the emergency call.

  Here, 'politseil' is in the adessive case, representing possession or people responsible for action.